title: Lineage-specific expansion of IFIT gene family: an insight into coevolution with IFN gene family.
abstract: In mammals, IFIT (Interferon [IFN]-induced proteins with Tetratricopeptide Repeat [TPR] motifs) family genes are involved in many cellular and viral processes, which are tightly related to mammalian IFN response. However, little is known about non-mammalian IFIT genes. In the present study, IFIT genes are identified in the genome databases from the jawed vertebrates including the cartilaginous elephant shark but not from non-vertebrates such as lancelet, sea squirt and acorn worm, suggesting that IFIT gene family originates from a vertebrate ancestor about 450 million years ago. IFIT family genes show conserved gene structure and gene arrangements. Phylogenetic analyses reveal that this gene family has expanded through lineage-specific and species-specific gene duplication. Interestingly, IFN gene family seem to share a common ancestor and a similar evolutionary mechanism; the function link of IFIT genes to IFN response is present early since the origin of both gene families, as evidenced by the finding that zebrafish IFIT genes are upregulated by fish IFNs, poly(I:C) and two transcription factors IRF3/IRF7, likely via the IFN-stimulated response elements (ISRE) within the promoters of vertebrate IFIT family genes. These coevolution features creates functional association of both family genes to fulfill a common biological process, which is likely selected by viral infection during evolution of vertebrates. Our results are helpful for understanding of evolution of vertebrate IFN system.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Zhang
authors.forename: Ting-Kai
authors.initials: TK
authors.lastname: Liu
authors.forename: Jian-Fang
authors.initials: JF
authors.lastname: Gui
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000235:genetics; D005399:Fishes / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D050838:Interferon Regulatory Factor-3 / Q000235:genetics; D050839:Interferon Regulatory Factor-7 / Q000235:genetics; D007372:Interferons / Q000235:genetics* / Q000494:pharmacology; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms / Q000145:classification / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D026801:Synteny; D014714:Vertebrates / Q000145:classification / Q000235:genetics*; D015027:Zebrafish / Q000235:genetics; D029961:Zebrafish Proteins / Q000145:classification / Q000235:genetics
chemical_list: D029941:Fish Proteins; D050838:Interferon Regulatory Factor-3; D050839:Interferon Regulatory Factor-7; D020033:Protein Isoforms; D029961:Zebrafish Proteins; D007372:Interferons; D011070:Poly I-C